[crankshaft] Remove the useless HMapEnumLength instruction.

src/crankshaft/arm64/lithium-arm64.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CRANKSHAFT_ARM64_LITHIUM_ARM64_H_
 #define V8_CRANKSHAFT_ARM64_LITHIUM_ARM64_H_
 
 #include "src/crankshaft/hydrogen.h"
 #include "src/crankshaft/lithium.h"
 #include "src/crankshaft/lithium-allocator.h"
@@ skipping 88 matching lines @@
   V(LoadFieldByIndex)                        \
   V(LoadFunctionPrototype)                   \
   V(LoadGlobalGeneric)                       \
   V(LoadKeyedExternal)                       \
   V(LoadKeyedFixed)                          \
   V(LoadKeyedFixedDouble)                    \
   V(LoadKeyedGeneric)                        \
   V(LoadNamedField)                          \
   V(LoadNamedGeneric)                        \
   V(LoadRoot)                                \
-  V(MapEnumLength)                           \
   V(MathAbs)                                 \
   V(MathAbsTagged)                           \
   V(MathClz32)                               \
   V(MathExp)                                 \
   V(MathFloorD)                              \
   V(MathFloorI)                              \
   V(MathFround)                              \
   V(MathLog)                                 \
   V(MathMinMax)                              \
   V(MathPowHalf)                             \
@@ skipping 1664 matching lines @@
 
 class LLoadRoot final : public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(LoadRoot, "load-root")
   DECLARE_HYDROGEN_ACCESSOR(LoadRoot)
 
   Heap::RootListIndex index() const { return hydrogen()->index(); }
 };
 
 
-class LMapEnumLength final : public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LMapEnumLength(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(MapEnumLength, "map-enum-length")
-};
-
-
 template<int T>
 class LUnaryMathOperation : public LTemplateInstruction<1, 1, T> {
  public:
   explicit LUnaryMathOperation(LOperand* value) {
     this->inputs_[0] = value;
   }
 
   LOperand* value() { return this->inputs_[0]; }
   BuiltinFunctionId op() const { return this->hydrogen()->op(); }
 
@@ skipping 1335 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CRANKSHAFT_ARM64_LITHIUM_ARM64_H_